ST. LOUIS -- Because Craig Counsell is a bigger home-run threat than Mark McGwire, the Arizona Diamondbacks are one win from sending the St. Louis Cardinals home for the winter.

Counsell, who had only four home runs all season, clubbed a game-winning three-run shot Friday night, while McGwire, benched and reduced to pinch-hitting, grounded into a game-ending double play as Arizona won Game 3 of the National League Division Series, 5-3, at Busch Stadium.

Arizona, which trailed 2-0 after five innings and was prepared to bring Curt Schilling back on three days rest if it faced elimination, leads the best-of-five NLDS two games to one and can advance to the NL Championship Series against Atlanta by winning Game 4 Saturday. Instead of burning 22-game winner Schilling, who threw a three-hit shutout in Game 1, the Diamondbacks will send 19-game loser Albie Lopez against Bud Smith and hold back Schilling for a Game 5, if needed, in Phoenix.

"It's a big swing game for us, no question about it. It's an emotional high for our ball club," said Luis Gonzalez, who snapped out of a 0-for-10 drought with a solo homer.

"[Saturday] is a must-win game for them; their backs are to the wall. They know if they don't win the season's over and if they do win, they have to come back to our place and see Schilling. We're hoping it plays to our advantage that [Saturday's game] is a day game."

Game 4 is scheduled for noon, but only if weather permits, and the National Weather Service is calling for a 90-percent chance of rain in the form of showers and thunderstorms.

The win went to Miguel Batista, but with Batista and opposing starter Darryl Kile going only six innings each, the two erratic bullpens came into play. That made the final three innings a wild adventure for all concerned, especially managers Bob Brenly of the Diamondbacks and Tony La Russa of the Cardinals.

Counsell -- no stranger to postseason heroics, as he scored the winning run in Florida's 1997 World Series championship -- homered off a 3-1 pitch from left-handed reliever Mike Matthews, who took over for Kile. It was the first home run off a left-handed pitcher in Counsell's Major League career, spanning 220 at-bats. But Counsell, who bats from the left side, had a breakthrough this year against lefties in average, hitting .337 in 101 at-bats.

"I dont hit any no-doubters, but I got it pretty good," Counsell said. "When I saw it in the seats, I let off some emotion. It's not the World Series, but it's huge for us. It's right there, one of my top two thrills, I'll give it that."

Matthews was left in long enough to allow four hits and was charged with three runs, which did not make La Russa very popular among the Busch Stadium sellout crowd.

"I thought Matthews just about got us out of it," said La Russa. "He threw a fastball down the middle and Counsell unloaded. Give Counsell credit. He got a pitch to hit and he hit it."

The Cardinals were not done. They cut into the lead with a solo home run by Edgar Renteria off Brian Anderson with two out in the bottom of the seventh inning. Then they put two runners on base against Mike Morgan in the bottom of the eighth.

Brenly brought in closer Byung-Hyun Kim with two out in the eighth and he immediately walked Albert Pujols to load the bases. But Jim Edmonds, whose fourth-inning homer staked the Cardinals to a 2-0 lead, flied out to center to end the threat.

Kim, rarely used for more than an inning this year, still had work to do in the ninth and it wasn't pretty. Pinch-hitter Kerry Robinson started it with a bunt that Kim bobbled, throwing late to first. Kim then walked Renteria. Mike Matheny was asked to bunt, but after fouling off a couple, he took a called third strike.

"If we get the bunt down, McGwire isn't hitting a double play," said La Russa. "This club's fundamentals are sound, but we had a couple of hiccups in the eighth and ninth innings and we lose a two-run game."

La Russa then tapped McGwire, who had been benched after starting Game 1 because of ailments to his leg and a resultant poor swing. McGwire swung and missed the first pitch, fouled back the second, took two balls, fouled off a breaking ball, then grounded to third, where Matt Williams stepped on the bag and doubled-up a gimpy McGwire at first.

Kim got the save despite control problems, walking two of the six batters he faced and unleashing a wild pitch, much to the dismay of Brenly. Asked if he was worried sending Kim out for the ninth, Brenly said: "No more worried than I am every time he goes out there."

Kile, rebounding from a season-finale fiasco against Houston, set an NLDS record with five consecutive strikeouts in the first and second innings. He was staked to a 2-0 lead on Edmonds' sky-high home run in the fourth inning. But Gonzalez cut the lead in half with his homer.

A leadoff walk to Williams in the seventh prompted La Russa to bring on Matthews. Steve Finley bunted into a force out, but Damian Miller followed with his second hit of the game, putting runners on the corners.

Pinch-hitter Greg Colbrunn blooped a single to tie the game, leaving runners on the corners for Tony Womack, who grounded sharply to second baseman Fernando Vina. Respecting Womack's speed, La Russa had the infield play up and Miller was erased at the plate.

Up stepped Counsell, who worked the count to his favor at 3-1. He sent the next pitch into the seats in right field, triumphantly raising both arms as he rounded first base. Counsell hit only four home runs in 458 at-bats during the regular season.

A gamer who plays hard, he is better known for doing just about everything except hitting home runs, but he wasn't even in the lineup for Game 2.

Kile escaped a first-and-second situation with two out in the third inning by getting Counsell on a tapper back to the box, but Arizona's threat the following inning presented a greater test for the Cardinals.

A pair of two-out walks to Mark Grace and Williams brought up Steve Finley, who had driven in both Diamondback runs in the series. Finley fell behind 0-2, then drove a 1-2 pitch up the middle. Grace has below-average speed and he proved it on this play.

On deck was Miller, who singled his previous at-bat, but third-base coach Chris Speier was not about to let this rare opportunity pass. While Edmonds, the Gold Glove center fielder, charged the ball, Speier sent Grace. Edmonds threw a one-bounce strike to Matheny, who patiently waited for Grace to arrive and tagged him high to end the inning.

It wouldn't be long before Edmonds would really make some noise. The bottom of the inning started with Placido Polanco's single, and when he took off for second attempting to steal, Miller couldn't get a grip on the ball and never made a throw. No. 3 hitter J.D. Drew bunted Polanco to third, as La Russa figured he had to play some small ball.

Batista retired the dangerous Albert Pujols on a bouncer to Williams, who made sure Polanco held.

But when Batista fell behind Edmonds, 2-0, with first base open, Batista pitched to him instead of walking him. And instead of playing small ball, Edmonds went deep, launching a 2-2 pitch on a sky-high trajectory that cleared the fence in right-center field only a few rows deep, but a few rows deep enough. It was the first St. Louis hit with runners in scoring position in 13 chances in the series.

"I was trying to make him hit it on the ground by keeping the ball down, but I wanted to show him one up and in and he got the good part of the ball," Batista said.